In Fourdrinier and other paper-making, cellulose-dewatering and asbestos-cement plate machines, it is a common practice to apply and doctor a wet pulpy mass of material adapted to form a web or hardened layer onto a water-permeable layer which is moved across support bodies as part of a drainage system whereby the excess water is removed through the liquid-permeable layer.
Liquid-permeable layer can be a sieve, a screen, a foil, a fabric, a needled or nonwoven felt, or any other member which facilitates extraction of the excess liquid by suction or by gravity or both from the pulpy mass through interstices of the liquid-permeable layer.
The support bodies over which this liquid-permeable layer is displaced can be bars, plates, lips or edges of suction boxes, suction plates or the like.
As the afore-mentioned copending application indicate, it is advantageous to make at least those portions of the latter bodies which are juxtaposed with the sieve, this term being used herein to refer to the liquid permeable layer in the most generic manner, of a hard abrasion resistant material, e.g. an oxide-type ceramic. This hard material is generally harder than the material of the sieve and more wear resistant than the latter.
It has also been proposed heretofore to mount the body of the hard material upon a support which acts as a stiffening torsion-resistant member limiting relative transverse movement between the hard material and the sieve which tends to damage the hard-material body.
However, difficulties have been encountered heretofore in connecting the hard-material body with such rigid and stiff supports so that the hard-material body is practically immobilized on its support except for minor expansion and contraction differences.